U0191: Lost Communication With Television
What to do
This is very often not a fault at all, and it is worth knowing before anybody charges you to investigate it.
Some cars were built with a television receiver — mostly large luxury cars, conversions and motorhomes. Nearly all of those tuners now receive nothing, because the broadcasts they were designed for have been switched off.
And on a car of that age, the unit has very often simply been taken out — during a stereo upgrade or a repair, or for the space. A module that has been removed but not coded out reports this fault forever, with nothing to find.
So the whole job is: check whether the equipment is still in the car, and if it is not, have the car told to stop expecting it.
Do that rather than ignoring it. A car that keeps calling for a module that never answers may not switch itself fully off after you lock it, and that flattens the battery over three or four days. That is the only real cost here.
What is not worth paying for is making an obsolete television work again. The transmitter is what disappeared, and no repair brings it back.
What this code means
The television module has stopped being heard from. The general reasoning is at U0100, and U0492 makes the honest point about this equipment — that the broadcasts these tuners were built for have been switched off across most of the world, so a module reporting no signal is telling the truth.
Silence takes that argument one step further, and it is worth being direct about it: on a vehicle old enough to have had a television, the module has very often been removed.
A tuner that receives nothing is dead weight, and they get taken out — during an infotainment upgrade, a repair, or simply for the space. A module physically removed and not coded out reports lost communication permanently, and there is nothing to find because there is nothing there. That is the commonest cause of this code by a wide margin on a vehicle of that age.
The second commonest is the opposite: a module the vehicle never had. Manufacturers reuse this code number for a video input or a rear screen, and a head unit or gateway taken second-hand from a better-equipped vehicle brings its configuration with it — the U0145 argument.
So the sequence is short and it is not a diagnosis. Establish whether the equipment is physically present. If it is not, code it out. If it is and the broadcasts it needs no longer exist, coding it out is still the sensible outcome — because a module that is not answering can keep the network awake after the vehicle is locked, and that flattens a battery in a few days. Paying to restore a dead broadcast standard is not an option worth offering anybody.
Likely causes
Start here
- Module not coded to the vehicle · specialist
- Aftermarket head unit fitted in place of the original · moderate
- Corroded or loose connector · easy
Less common
- Second hand module locked to another vehicle · specialist
- Blown fuse or failed supply · easy
- Damaged data bus wiring · moderate
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
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